Semi-automatic or automatic guns



B. MAILLARD SEMI-AUTOMATIC OR AUTOMATIC GUNS May 31, 1966 Filed Sept.14, 1964 6 Sheets-Sheet 1 May 31, 1966 B. MAILLARD SEMI-AUTOMATIC ORAUTOMATIC GUNS 6 Sheets-Sheet 2 Filed Sept. 14, 1964 May 31, 1966 B.MAILLARD SEMI-AUTOMATIC OR AUTOMATIC GUNS 6 Sheets-Sheet 5 Filed Sept.14, 1964 IIIIIII/III/I/III/ May 19676. B. MAILLARD 3,

SEMI-AUTOMATIC 0R AUTOMATIC GUNS Filed Sept. 14, 1964 6 Sheets-Sheet 4 y1, 1966 B. MAILLARD 3,253,513

SEMI-AUTOMATIC OR AUTOMATIC GUNS Filed Sept. 14, 1964 6 Sheets-Sheet 5May 31, 1966 B. MAILLARD 3,253,513

SEMI-AUTOMATIC OR AUTOMATIC GUNS Filed Sept. 14, 1964 6 Sheets-Sheet 6 IWI ll/ll/IVI/A United States Patent 3,253,513 SEMI-AUTOMATIC 0RAUTOMATIC GUNS Bernard Maillard, Geneva, Switzerland, assignor toBrevets Aero-Mecaniques S.A., Geneva, Switzerland Filled Sept. 14, 1964,Ser. No. 396,033 Claims priority, application Luxembourg, Sept. 19,1963,

4 Claims. ici. 89190) The present invention relates to at least partlyself acting gun-s, this term including automatic and semi-automaticguns, advantageously of a caliber ranging from 20 to 50 mm., comprisinga breech body having longitudinal displacements, which breech body isfitted, on the one hand, with at least one locking member controlled byat least one control member having longitudinal displacements andpreferably carrying a firing pin, said control member being housed in arecess provided in said breech body and open at the rear to permit theintroduction of said control member in the longitudinal direction, and,on the other hand, with at least one spring urging said control memberfrontwardly by reaction on the breech body, said breech body driving thecartridge feed mechanism and being the only element of the breech to beguided by the breech casing.

It is known that semi-automatic and automatic guns are automaticallyreset after every shot, the firingof the next shot either requiring anoperation of the gunner (semiautomatic guns), or not (automatic guns).

The gun according to the present invention is characterized by the factthat said spring bears, at the front, on said control member and, at therear, on a cap closing at least partly said recess toward the rear andfreely slidable with respect to the breech block, said cap having asubstantial mass so that it can contribute, by inertia, once the breechbody has come into closing position, in pushing the control membertoward the front,

The advantage of this arrangement lies in a gain of time obtained in thelocking and firing operations.

A preferred embodiment of the present invention as applied to the caseof a machine gun'will be hereinafter described with reference to theappended drawings, given merely by way of example, and in which:

FIG. 1a is an axial substantially vertical section of a portion of amachine gun according to the present invention;

FIG. lb is a section in the same plane as that of FIG. 1a showing theportion of said machine gun located directly behind that illustrated byFIG. la;

FIGS. 2a and 2b are substantially vertical sectional views correspondingto FIGS. 1a and 1b, slightly offset with respect thereto;

FIGS. 3a and 3b are axial horizontal sections corresponding to FIGS. 1aand 1b;

FIG. 4 is a cross section of the line IV--IV of FIG. 2a;

FIG. 5 is a cross section of the line VV of FIG. 2a;

FIG. 6 is a cross section of the line VI-VI of FIG. 2b;

FIG. 7 is a cross section of the line VIIVII of FIG. 2b;

FIG. 8 is a cross section of the line VIII-VIII of FIG. 2b;

FIG. 9 is a cross section of the machine gun line IX- IX of FIG. 2b;

FIG. 10 is a half cross section of the machine the line XX of FIG. 2b;

FIG. 11 is an end view of the machine gun seen from the right hand sideof FIG. 2b;

FIG. 12 shows, on an enlarged scale, the cartridge chamber of themachine gun;

machine gun on the machine gun on the machine gun on the machine gun onthe machine gun on the on the gun on ice FIG. 13 shows, on an enlargedscale, a detail of the structure illustrated by FIG. 3a;

FIGS. 14 and 15 show, similarly to FIG. 2b, two modifications,respectively, of a machine gun according to the present invention.

The following description relates to the case of a heavy machine gun,for instance of a caliber equal to 20 mm.

This gun comprises a tubular breech casing 1 of circular cross sectionand of substantially uniform diameter and thickness (the outer diameterbeing of the order of -130 mm). Said breech casing 1 is provided, in itsupper part, with an opening 2 adapted to receive a cartridge feedmechanism and in its under part, with an opening 3 for the ejection ofspent cartridge cases. This breech casing 1 constitutes a kind of framein the form of a tubular beam having a maximum rigidity for a givenweight of metal.

Breech casing 1 may be made from a section of a tube, for instance ofdrawn and treated steel. It may also be made of two halves assembled,for instance by welding, along generatrices. Anyway, the machining ofthe breech casing can be made essentially by boring and turning and itsmanufacture is therefore particularly simple and economical.

In this breech casing 1 there is rigidly fixed a sleeve 5 to which thebarrel 7 of the gun is fitted in a removable rnanner, through a bayonetjoint 6. Sleeve 5 is provided, near the rear end thereof, with areinforcing flange 8 the external diameter of which is equal to theinternal diameter of breech casing 1. Said breech casing 1 is provided,on the inside thereof, with an annular groove 9 adapted to accommodate aresilient split ring 10 projecting inwardly with respect to the innerwall of breech casing 1 and acting as a rear abutment for sleeve 5. Atits front end, breech casing 1 is provided with internal screw threads11 cooperating with a nut 12 forming a front abutment for sleeve 5 bycontact with a shoulder 13 thereof. Nut 12 carries a fixation lever 14resiliently acted upon by a spring and capable, on the one hand, byengagement into a longitudinal groove 15 of barrel 7, of fixing saidbarrel with respect to sleeve 5, thus preventing it from disengagingfrom bayonet joint 6, and, on the other hand, of blocking nut 12 withrespect to breech casing 1. The greatest portion of sleeve 5, extendingfrom flange 8 to shoulder 13, is of cylindrical outer shape and has anexternal diameter smaller than the internal diameter of breech casing 1.In the elongated annular space thus left free between sleeve 5 andbreech casing 1, there isprovided, at the rear, a fixed invertedU-shaped strap 16 open at its lower end (see FIG. 4) and, extending fromfront to rear, several recoil absorbing springs 17. Fixed strap 16 hasan external surface fitting to that of the inner wall of breech casing1, which can therefore slide with respect to said strap. There are foursprings 17 disposed symmetrically with respect to the axis of the barrel(see FIGS. 1 and 4), said springs being of helical shape and each woundabout a tubular guide 18 which bears at the rear against strap 16through a flange 19 integral with said guide 18. Each of the s rings 17bears, at the rear, on said flange 19 and, at the front, through a cap20 wherein guide 18 is slidable, on shoulder 13. Nut 12 is provided withan annular recess 21 open at the rear and into which fixed guides 18slide freely when the gun is recoiling.

Strap 16 is secured to a tubular support 22 within which breech casing 1is slidable. Support 22 is itself carried by a mount (or turret),through trunnions 23 which permit of aiming the gun for elevation. Strap16 is secured to support 22 through two vertical spindles 24 disposed oneither side of sleeve 5 in the same plane perpendicular to the axis ofthe barrel, said spindles extending, on the one hand, without play, inpassages 25 provided in the vertical branches of strap 16, on the otherhand, with a longitudinal play, through cylindrical breech casing 1,owing to the provision of elongated guiding slots 26 (FIG. 3a) and,still on the other hand, Without play, through holes 27 of tubularsupport 22. Thus the whole of breech casing 1, sleeve 5 and barrel 7 canrecoil on every shot with respect to support 22, the recoil movementbeing absorbed by springs 17 which act between the shoulder 13 of sleeve5 and strap 16 rigid with the non recoiling support 22.

Furthermore, due to the fact that there is no peripheral play betweenspindles 24 and their hous ngs, said whole is angularly fixed withrespect to support 22.

Inside breech casing 1 and immediately at the front of the upper opening2, there is provided a cartridge feed device front support 28 the outersurface of which has, at least partly, as shown by FIG. 5, the shape ofa portion of a circular cylinder fitting in the inner Wall of breechcasing I. Support 28 is provided with two vertical extensions 29 throughwhich passes a spindle 30 forming the pivot axis for the lid and theunder part 4:: of the feed device. Extensions 29 fit against the edges31 of an opening provided at the upper part of breech casing 1, thusangularly securing support 28. Support 28 is provided with a frontabutment 33 in contact with the flange 8 of sleeve 5 and it is incontact at the rear with the above mentioned split ring 19 which engagesinto a recess 32 provided in said support 28. Support 28 is furtherprovided with a horizontal fiat face 3311 held in contact with acorresponding fiat face provided upon the fiange 8 of sleeve 5. Saidsleeve 5 is therefore prevented from turning with respect to breechcasing 1 by support 28 which is itself prevented from turning withrespect to said breech casing 1 as above explained. Support 28 furtheracts as deflecting means for the cartridge A that is being introducedinto the cartridge chamber and, for this purpose, it is provided with acurved under face 28a for the guiding of said cartridge.

The gun includes a movable breech which essentially comprises a breechbody 34 in which is slidably mounted with a limited amplitude ofmovement a firing pin 35. This firing pin 35 is urged frontwardly withrespect to breech body 34 by a firing pin spring 36 as far as theposition shown by FIGS. 2a, 3a and 13 wherein the front point of firingpin 35 projects to the outside of breech body 34. As shown by FIG. 5,the middle portion of firing pin 35 has a substantially rectangularcross section elongated in the horizontal direction. The front end offiring pin spring 36 bears against the bottom of a recess 37 providedat, and open toward, the rear end of firing pin 35 and the rear end ofsaid spring 36 bears against the end of face of a plug or cap 33, ofgeneral cylindrical shape, provided at its front with two lateralprojections 38a. As shown by FIG. 13, breech body 34 is provided with abore 34c of a diameter equal to D followed by two half cylindricalhousings 34b disposed symmetrically with respect to the vertical planepassing through the axis of said breech body 34 and intended toaccommodate projections 38a of cap 38. Said cap 38 is mounted in breechbody 34 by being driven (with its projections 38a directed vertically)through a vertical recess 3411 (FIG. 6) provided in the rear portion ofbreech body 34, and through a bore 34a of a diameter d smaller than D,thus compressing spring 36, after which cap 38 is turned through 90about its longitudinal axis and then released, the pressure of firingpin spring 36 applying the rear fiat surface of each projection 33aagainst a shoulder 34d of the corresponding housing 34b.

Breech body 34 is provided, at the rear thereof, with said bore 34aintended to accommodate the cylindrical portion, of diameter d, of cap38. As shown by FIG. 2a, breech body 34 is provided with vertical andlongitudinal slots extending frontwardly from the rear thereof as far asan abutment face 67, so that bores 34c and 34a are open laterally, inorder to permit of mounting from the rear firing pin 35 and cap 38. Itwill be understood that cap 38 is movable frontwardly in housings 34])the shape of which is such as to prevent said cap 33 from rotating aboutits axis. The whole is arranged in such manner that, in operation, cap38 does not come into contact with a second shoulder 34c forming thefront face of bore 340.

Firing pin spring 36 is a helical spring and a cylindrical floatingmember 39 is located in said spring. This member 39 preferably has anaxial length c such that it fills up the space available between therear end face of cap 39 and the bottom of the recess 37 of firing pin 35when the latter is in its rear end position. As visible in FIG. 13, cap38 is provided with a recess 38b against the bottom of which spring 36bears and against which member 39 is also applied when it is in itsrearmost position. Of course, before assembling cap 38 to the breechbody, member 39 is placed in spring 36.

In its closing position (FIGS. 2a and 3a), the front portion of breechbody 34 is housed between two arms 50 which form rearward extensions ofsleeve 5, integral therewith, flange 8 being located at the level ofarms 5a. In the front portion of breech body 34 and disposedsymmetrically with respect to the vertical plane passing through theaxis of barrel 7, are housed two locking members 40 which bear at therear against the rear faces of a recess 41 extending verticallythroughout breech body 34, said locking members 40 bearing at the frontagainst semicylindrical surfaces 42 of breech body 34. The inner sidesof locking members 40 are each provided, at the rear thereof, with acentral projection 43 housed in a corresponding recess 41 of breech body34 so as to be flush with the vertical Walls of a passage 34- whichconstitutes a guide in the breech body 34. Each projection 43 includes alocking face 43a and, at the rear, a spreading face 43b adapted to bepushed outwardly, by an oblique face 44 carried by firing pin 35, intothe position shown by FIGS. 3a and 13. In this position, a locking face45, provided at the rear of each locking member 40, comes into Contactwith a cooperating locking face 46, provided in the inner surface ofeach of the arms 5a of sleeve 5. In this position, firing pin 35, bycontact with the locking faces 43a of locking members 49, prevents saidmembers from pivoting inwardly. Faces 45 and 46 have an inclination withrespect to the direction of the forces transmitted from breech body 34to its locking members 40 such that, account being taken of the relativefriction coefiicient of the constituting materials of locking members 40(face 45) and breech body 34 (face 46), any effort exerted in therearward direction upon locking members 40 tends to drive them towardthe inside.

In order to produce the movement of retraction of firing pin 35 which isnecessary to permit of releasing breech body 34, there is provided (FIG.2a) a gas tap from barrel '7. For this purpose, a cylinder 47 isprovided in a projecting ridge 48 of sleeve 5, at the front lowerportion thereof, this ridge 48 being located between the verticalbranches of strap 16 and being tangent to the inner surface of breachcasing 1 (FIG. 4). As shown by FIG. 2a, cylinder 47 is closed at thefront by a plug 49 kept in position by nut 12, both longitudinally byabutment against said plug 49 and in rotation by means of a projection49a engaged between sleeve 5 and the inner Wall of nut 12. This plug 49is provided with a calibrated orifice 50 which communicates, through ahole 51 provided in sleeve 5 and a radial passage 52 provided in barrel7, with the front end of the cartridge chamber 53 of the gun.

The front portion of a piston 56, slidable in cylinder 47, is providedwith a recess 57 forming, together with a recess 58 provided in plug 49,an expansion chamber intended, in combination with calibrated orifice50, to delay the action of the powder gases upon piston 56. The rearportion of said piston 56 is provided with a recess 59 located in itslower part and in which is housed a return spring 60 the front end ofwhich bears upon the end wall of recess 59 and the rear end of whichbears upon a support 61. This support 61 has an outer transverse crosssection corresponding to the inner transverse cross section of breechcasing 1 and it is fitted in sleeve 5 before its introduction into thebreech casing, by sliding in a direction perpendicular to the axis ofsaid breech casing. Furthermore, support 61 bears in the rearwarddirection against split ring 10.

The rear edge 62 of piston 56 cooperates with firing pin 35 and breechbody 34 in the following manner. At its lower part, breech body 34 isprovided with a smooth bore 63 the longitudinal axis of which is locatedin the vertical plane of symmetry of breech casing 1. In this bore 63there is mounted, slidable with a limited amplitude parallelly to theaxis of the barrel, a push-piece 64 provided at its end with atransverse flange 65. This flange 65 is engaged in a transverse groove66 provided in the body of firing pin 35. Thus, push-piece 64 is maderigid with firing pin 35 (which cooperates with the above mentionedabutment face 67 provided on breech body 34) to limit the displacementof said firing pin 35 toward the front with respect to breech body 34,that is to say to limit the distance by which the front end point offiring pin 35 projects frontwardly from breech body 34. When firing pin35 is in position for firing, push-piece 64 projects frontwardly fromthe portion 68 of breech body 34 that surrounds said push-piece by alength f which is equal to the distance firing pin 35 must move backwith respect to breech body 34 to permit release of the breech.

Thus, when powder gases escape through radial passage 62, they push backpiston 56, which slides toward the rear cylinder 47 and acts against theaction of spring 60 (while sliding along support 61) through its rearedge 62 upon push-piece 64 to cause it to slide back a distance equal to1, this movement being transmitted, through the flange 65 of push-piece64, engaged into the groove 66 of firing pin 35, to said firing pin 35.When piston 56 has moved back a distance equal to its rear edge 62 comesinto contact with the front face of the portion of breech body 34 thatsurrounds push-piece 64 and the rearward movement of piston 56 is thentransmitted both to firing pin 35 and to breech body 34.

Breech body 34 may be provided with a recess 69 to reduce its weight.

In its reciprocating movement, breech body 34 is guided by twolongitudinal slideways diametrally opposed to each other inside breechcasing and located at the same height. Each of these slideways comprisesa front element 70 and a rear element 71. Said elements 70 and 71 areglued to the inner wall of breech casing 1 and riveted thereto. Each ofsaid elements comprises two substantially parallel wings 72 disposedsymmetrically with respect to the horizontal plane passing through theaxis of breech casing I. Said wings are integral with a 'web 73 theshape of which conforms with that of the inner wall of breech casing 1,the whole of web 73 and wings 72' having a U-shaped section. As shown byFIG. 6, breech body 34 cooperates with the wings 72 of the slidewaysonly along the inner edges thereof, owing to angular contact surfaces 74provided at four places on breech body 34. Thus, elongated spaces areleft between breech casing 1 and the volume. swept by the breech, bothon the inside and on the outside of slideways 71 and 72, which spacesare used as it will be hereinatfer explained for housing some mechanismsof the gun.

A first mechanism housed between the wings 72 of the left hand sideslideways (FIGS. 6 to 8) consists of an elongated tubular cam 75 foractuating the cartridge feed mechanism of the gun. This cam 75 isadapted to oscillate about its longitudinal axis, which is-parallel tothat of barrel 7 but is offset laterally with respect thereto, owing toits mounting between two thrust hearings, to wit a front bearing 76provided in a transverse partition rigid with the rear portion of thatof the left hand front slideway element 70 and a rear bearing 77provided in a rear plate 78. The plate 78 is kept in positionlongitudinally by being tightly held between the ends of the rearslideway elements 71 and the front face of a concave closing block 79and, in rotation, by engagement of the rear edges of the wings 72 ofsaid elements between projections 79a provided on the front wall of saidplate 78, which projections further prevent deformations of wings 72.Block 79 is fixed in a removable manner at the rear of breech casing 1,for instance through a bayonet joint 80, this block 79 being preventedfrom dissengag-- ing by rotation owing to the provision of a lockinglever 81 analogous to lever 14, Plate 78 is provided with an elasticloclcwire 82 serving merely to prevent said plate from escaping frombreech casing 1 when block 79 is removed.

Cam 75 is of a length averaging that of the stroke of breech body 34(which stroke is visible by comparison between FIGS. 1a, 1b and 2a, 2b)and it extends from the rear end of breech casing 1 at least to the rearedge I of the cartridge A which is being introduced (FIG. lb).

The front portion of this cam 75 therefore extends above ejectionopening 3, not vertically over it, but on the left thereof when lookingtoward the front, as shown by FIGS. 3a and 6. Cam 75 is provided with ahelical slot 83 in which is engaged a finger 84 rigid with andprojecting from the left hand side of breech body 34 (FIG. 6) and at therear end thereof (FIGS. 1 and 3a), said finger being locatedapproximately in the horizontal plane passing through the axis of breechcasing 1. During operation, finger 84 remains constantly engaged in slot83. It will be understood that, in its to-and-fro movement, the breechcauses cam 75 to rotate about its horizontal axis through an angle ofabout 150.

The feed mechanism is advantageously'of the'type described in US. PatentNo. 3,198,075 as well as in the Luxembourg patentapplication No. 40,215,of June 2, 19-61, and in the addition thereto No. 40,296, of June 21,1961. It comprises a lever 85 guided by rollers 86a carried by twospindles 86 fixed to lid 4 and which is slidable transversely with areciprocating translation movement to perform the feed of a cartridgebelt and also the successive feed of the cartridges of said belt toposition A. The vertically bent end 85a of this lever 85 carries aroller 87 engaged in a transverse slot 88 of breech casing 1 located inthe upper portion of said breech casing. In order to transmit themovement of cam 75 to roller 87, which must move in the transversedirection, a toothed portion 89 of cam 75 cooperates with a toothedsector 90 liaving therein a recess 91 in which roller 87 is slidablyheld (FIG. 7). As shown by FIG. 3, toothed portion 89 is provided aboutat mid length of cam 75 and the ends of said cam engaged in bearings 76and 77 are practically identical so that cam 75 can be mounted witheither end thereof at the front.

Toothed sector 90 is housed wholly on theinsideof breech casing 1 and itis located at the rear of the rear end of opening 2 serving to theintroduction of cartridges. The external surface 90a of toothed sector90 conforms exactly to the internal surface of breech casing 1 whichthus constitutes a guide for said sector 90. In order to have sector 90in tight contact with the inner wall of breech casing 1 while being inmesh with the toothed portion 89 of tubular cam 75, the web 73 ofslideways 71, in which said cam is mounted, is provided with a passage92 the front and rear edges of which guide the sides 90b of toothedsector 90. Finally, above slideways 71, the inner face of toothed sector90 is further guided by the external wall of a support 93 which will behereinafter referred to. Thus, in all its positions, toothed sector 90is tightly guided and held in all directions and it can thereforetransmit to the lever 85 of the breech mechanism, through roller 87, themovements of oscillation of cam 75.

Toothed sector 90 has, transversely, a shape and dimensions such that,account being taken of the positions and 7 dimensions of slidew'ays 71,it can be brought by rotation (in the clockwise direction, FIG. 7) to aposition where it is cleared by said slideways, above them, whichpermits of mounting it by longitudinal translation after disengagementof roller 87.

A second mechanism of the gun, housed between the wings 72 of the righthand side slideway 71, is a mechanism for stopping firing. It includes asear 94 and its shock absoring device comprising for instance a spring95 and its tubular guide 96. Sear 94 and guide 96 are mounted about apin 97 which extends through slots 98 provided in the wings 72 of theright hand side slideway 71, these slots limiting the deformations ofspring 95 during the operation. Sear 94 has a stop face 94a whichcooperates with a stop face 99 (FIG. 6) provided on the breech body 34.Sear 94- is further provided with a spring mounted return piston 100which urges said sear 94 toward the inside of breech casing 1. The web73 of slideway '71 is provided with a recess 101 the front edge 102 ofwhich recess forms an inclined plane capable of fully ensuring theengagement of sear 94 with the stop face 99 of breech body 34 when,during the compression of spring 95, the face 94b of said sear 94reaches said front edge 102. The lower edge of support 93 has, above theend of pin 97, an abutment surface 930 capable of preventing said pinfrom moving out from slots 98 (FIGS. 7 and 10). Finally, guide 96,through the rear portion of which pin 97 extends, may be maintained atthe front by sliding in a hole 103 provided in a transverse partition104, said partition belonging to the rear portion of the right hand sidefront slideway 70.

In an elongated space located under the lower wing 72 of the left handslideway is housed a third mechanism consisting of a return spring 10 5,of helical shape, disposed about a longitudinal tubular guide 106. Thisguide 106 is maintained at the front by support 61 and at the rear byclosure block 79 in which it is secured by a self locking device. Returnspring 105 bears at the front against a cup shaped member 107 integralwith breech body 34 and projecting therefrom downwardly toward the left,as shown by FIGS. and 6. Guide 106 bears upon closure block 79 throughtwo pins 110 belonging to a plug 109 rigid with guide 106 and againstwhich spring 105 is bearing. On the outside thereof, closure block 79 isprovided with two recesses 111 to accommodate the ends of two stoplevers 108 in the locking position shown by FIGS. 1 and 11, whereinlevers 108 are urged by a spring 1 12. Pins 110 cooperate with a groove113 provided in block 79, so as to form a kind of bayonet joint. Inorder to disengage guide 106, it therefore sufiices to bearsimultaneously upon the inner ends of levers 108 against the action ofspring 112, for instance by means of a screwdriver, which disengagesthese levers from recesses 111 and permits of rotating plug 109 in thedirection which disengages pins 110 from groove 113. Spring 105 thenpushes plug 109 and guide 106 outwardly. It should be noted that thisguide 106, and also spring 105, pass through a notch 78a provided inplate 7 8 in order to permit of removing the breech body.

In the elongated space located below the lower wing 72 of the right handside slideway are housed the essential elements of a fourth mechanism,to wit the resetting mechanism. This mechanism comprises a chain 114guided in a tubular guide 115 in such manner that, by rotation of apinion 116 in mesh with said chain 114, it is possible either to pullsaid chain rearwardly for resetting the gun or to push it in thedirection which places the chain out of action. Guide 115 is held,longitudinally, at the front by support 61 (FIG. 5) and at the rear by aprojection 117 integral with a plate 78, and, laterally, by thecooperation of fins 118 rigid with guide 115 with the inner wall ofbreech casing 1. Guide 115 is provided with a longitudinal slot 119(FIGS. 2a and 7) from which projects a slider 120 connected with thefront end of 8 the chain and adapted to come into contact with the rearportion of a hooking projection 121 carried by pushpiece 64 at thebottom part of the right hand side thereof.

Pinion 116 is fixed on a spindle 122 which extends throughout the rearportion of breech casing 1, as shown by FIG. 8, and also through thewings 72 of the right hand slideway 71. Upon the portion of spindle 122that projects downwardly from breech casing .1 there is fixed a cranklever 123. In order to reset the gun, it suffices to rotate this lever123 in the direction that moves toward the rear, first, slider andconsequently push-piece 64- and firing pin 35, and then, after thelocking members 40 have been released by locking faces 43a, breech body34 by contact of firing pin 35 with plug 38. During the resettingoperations, the portion of chain 114 located at the rear of pinion 116can move out laterally from breech casing 1 through a passage 124 (FIG.8).

The four mechanisms which have been described (cam 75, sear 94 withdamping device 95-96, return device 1054106 and resetting mechanism 114-41 15) extend from the rear of breech casing 1 to at least thetransverse plane passing through the rear edge I of the cartridge A thatis being introduced (FIG. 111). It is still possible to house at leastone other mechanism in the elongated space located above the upper wings72 of the slideways rearwardly of said rear edge, such a mechanism beingan ejector with a damping device and/or a rod for stopping the gun afterthe last shot, with the breech open.

For this purpose, on the trajectory of the spent cartridge cases whichare driven rearwardly by an extractor 125 (FIG. 2a) carried by breechbody 34, there is mounted an ejector 126 (FIG. 1b) slidable on two rods127 (FIGS. lb, 7 and 8) fixed parallelly to the axis of breech body 1,between two transverse walls 93a and 93b integral with support 93 (FIG.1b). Between the rear of ejector 126 and the rear transverse Wall 93a,there is provided around each rod 127 a juxtaposition of damp ingsprings 128. As shown by FIGS. 2, 5 and 6, breech body 34 is provided atits upper end with a longitudinal recess 34 for the passage of ejector126. Furthermore, above rods 127 and in the vertical plane passingthrough the axis of breech casing 1, there is mounted, slidable in walls93a and 931), a rod for stopping the gun after the last shot, the breechbeing open, said rod being esignated by reference numeral 129 (FIGS. lband 6). Such a rod is moved frontwardly, when the feed mechanism isemptying, against the action of a return spring 130 and then causesbreech body 34 to be caught by sear 94.

Support 93, at the rear of toothed sector 90, has anexternal shapecoinciding with that of the inner wall of breech casing 1 and it issecured thereto through a transverse removable spindle 131 (FIGS. lb, 2band 10), which extends throughout breech casing 1 and support 93 as moreparticularly visible on FIG. 10. Support 93 may further be held incontact with the upper wings 72 of slideways 7 1. The ends 131a ofspindle 131 project from breech casing 1 so that hooks 132, pivotableabout a spindle 133 carried by the lid 4 of the feed mechanism, canengage under said ends so as to keep the lid closed. In this position,spindle 13 1 is secured not only by a resilient pin 134, extending boththrough breech casing 1 and through support 93 and engaging in a groove135 provided in spindle 131, but also by the sides 4b of lid 4, whereaspin 134 is itself secured by spindle 133 which is then above it.

In order to actuate sear 94, there is provided a trigger mechanismsupported by spindle 122, on which it is mounted loose. Such a mechanismincludes, on the outside of breech casing 1 and on the side opposed tocrank lever 123, a trigger lever 136 and, on the inside of said breechcasing 1, an inter-mediate lever 137 connected through dog clutch meanswith trigger lever 136 and a second intermediate lever 138 connected tothe first one 9 through an equalizer bar 139 subjected to the influenceof stop rod 129.

Finally, the gun comprises a damping and accelerating spring 140 housedin closure block 79 and bearing at the front upon a rigid abutment ring141 projecting to the outside of block '79. Spring 140 is keptcompressed by a split ring 142 which limits the frontward displacementof ring 141, ring 142 being housed in a groove provided at the front ofblock 79. Plug 38 is arranged to come into abutment with ring 141 at thesame time as the breech body and it is provided for this purpose with ashoulder 38c which is joined to the rear face 34g of breech body 34 soas to form together a surface fitting with that of abutment ring 141.

This gun works as follows:

Before firing, the elements are in the positions shown by FIGS. 1a and1b. Breech body 34 is held in rear position by sear 94 and a cartridge Ais in position for being introduced into the gun. Firing pin 35 is heldrearwardly with respect to the breech body against the action of spring36, by contact of its oblique faces 44 with the spreading faces 43b oflocking members 40, which are kept inside recesses 41 by contact offaces 430 with the wings 72 of slideways 71.

By acting upon trigger lever 136, the gunner causes breech body 34 to bereleased from sear 94. The breech (breech body 34, push-piece 64,extractor 125, firing pin 35, locking members 40, plug 38) is driventoward the front by spring 105 and pushes cartridge A into chamber 53.Once the breech body has reached its front position, shown by FIGS. 2aand 3a, firing pin 35 which, up to then, was held toward the rear of thebreech body as above described is projected toward the front by theeffect of its inertia and under the thrust of spring 36. By contact ofits oblique faces 44 with the faces 43b of the locking members 40,firing pin 35 drives locking members 40 outwardly into the positionshown by FIGS. 3a and 13, and passes between the locking faces 43a oflocking members 40, which locks the breech body in position. Firing pin35 is thrust in its frontward movement by the mass of plug 38 whichkeeps moving frontwardly under the effect of inertia against the actionof spring 36, which spring is compressed until it stops said plug 38 andpushes it back toward the rear. At the same time, floating member 39 isprojected toward the front by inertia, which movement, on the one hand,further facilitates the relative displacement of firing pin 35 towardthe front with respect to breech body 34 and, on the other hand,prevents rebounding of said firing pin toward the rear. After firing ofthe cartridge, powder gases from barrel 7 act on piston 56 which firstacts only upon push-piece 64 in order to push back firing pin 35 towardthe rear and to permit retraction of locking members 40 inwardly. Thensaid piston 56 acts directly upon breech body 34, which causes it tomove rearwardly, such a rearward movement being further produced by theresidual pressure of the gases on the breech body through the cartridgecase. At the end of the recoil stroke, breech body 34 comes into contactwith abutment ring 141 and compresses spring 140 which sends it backtoward the front. During the recoil movement, engagement of the finger84 of breech body 34 with the helical slot 83 of cam 75 causes said carnto rotate about its axis and, through toothed sector 90, it actuates thefeed mechanism which brings a fresh cartridge into waiting position A.Then the above described cycle is repeated either until the gunnerceases to act upon trigger lever 136 or until rod 129 automaticallycauses the breech body to be caught by sear 94. It should be noted that,on every shot, the whole of barrel 7, sleeve and breech casing 1 recoilsin support 22 against the action of absorbing springs 17.

The feed mechanism, instead of being fixed to breech casing 1 and thusof participating in the recoil movement of the gun as in the arrangementabove described, might be carried by an element rigid with support 22,in which 10 case it would not participate in the recoil movement. Inthis case, it suffices to provide between toothed sector and the feedmechanism a connection permitting relative displacement due to recoil.FIGS. 14 and 15 illustrate two such connections given by way of example.

In the construction of FIG. 14 the feed device comprises a fixed lid 40and a sliding member 143 which is to be given a horizontal reciprocatingtranslatory movement. The connection then consists in the followingelements:

External teeth 144 carried by a toothed sector 90c analogous to thetoothed sector 90 of FIGS. 1b, 2b, 3 and 7 and which is at least partlyhoused in breech casing 1, said teeth 144 having the same axis as saidbreech casing;

A toothed sector 145 carried by a spindle 146 journalled on lid 4cthrough bearings 147, this toothed sector 145 having its axis incoincidence with the oscillation axis defined by said bearings 147, and

A. second toothed sector 148 also carried by spindle 146 and in meshwith a rack 149 carried by sliding member 143.

Sector 145 has a width a greater than that of teeth 144 by an amount bof the order of the recoil stroke of breech casing 1, so that sector 145is always in mesh withteeth 144.

In the construction of FIG. 15, the feed mechanism comprises a fixed lid4d and a sliding member 150 movable with a longitudinal reciprocatingtranslatory motion, this member 150 being guided, in the same manner asthe lever 85 of FIGS. 10, 1b and 2a, 2b, by means of two spindles 86 androllers 86a. The connection between toothed sector 90d and the feedmechanism comprises a roller 151 carried by toothed sector 90d on theoutside of breech casing 1 and cooperating with an elongated groove 152provided in sliding member 150. In order to keep roller 151 engaged ingroove 152, said groove has, in a direction parallel to the axis ofbreech casing 1, a length greater than the above mentioned value b.

In a general manner, while the above description discloses what isdeemed to be practical and eflicient embodiments of the presentinvention, said invention is not limited thereto as there might bechanges made in the arrangement, disposition and form of the partswithout departing from the principle of the invention as comprehendedwith the scope of the appended claims.

What I claim is:

1. An at least partly self acting gun which comprises, in combination,

a breech casing,

a breech body guided in said breech casing so as to be slidablelongitudinally therein, said breech body being provided with alongitudinal recess opening into the rear face of said breech body,

cartridge feeding means operatively connected with said breech body,

at least one looking member movably carried by said breech body andadapted to cooperate with said breech casing,

at least one control member slidable longitudinally in said recess ofsaid breech body for actuating said locking member to move it intocooperating locking position with respect to said breech casing,

a cap located opposite said recess slidably mounted longitudinally withrespect to said breech body and free from contact with said breechcasing,

abutment means carried by said cap and said breech body for limiting therearward displacement of said cap with respect to said breech body,

and resilient means interposed between said cap and said breech body forurging said breech body frontwardly with respect to said cap.

2. A gun according to claim 1 wherein said resilient means consist of alongitudinal coil spring and said cap 8,2 l 1 is shaped and arranged toform a housing for the rear of said spring.

3. An at least partly self acting gun which comprises,

in combination,

a breech casing,

a breech body guided in said breech casing so as to be slidablelongitudinally therein, said breech body being provided with alongitudinal recess opening into the rear face of said breech body,

cartridge feeding means operatively connected with said breech body,

at least one locking member movably carried by said breech body andadapted to cooperate with said breech casing,

at least one control member slidable longitudinally in said recess ofsaid breech body for actuating said locking member to move it intocooperating locking position with respect to said breech casing,

a cap located opposite said recess slidably mounted longitudinally withrespect to said breech body and free from contact with said breechcasing, said cap 12 being provided with a frontwardly open longitudinalrecess,

abutment means carried by said cap and said breech body for limiting therearward displacement of said cap with respect to said breech body,

a spring interposed between said cap and said breech body for urgingsaid breech body frontwardly with respect to said cap,

and a plunger member freely slidable longitudinally in said secondmentioned recess adapted to strike said control member.

4. A gun according to claim 3 wherein said spring is a helical springhaving its axis parallel to the longitudinal direction of the gun, saidfreely slidable member being housed inside said spring.

No references cited.

BENJAMIN A. BORCHELT, Primary Examiner.

F. C. MATTERN, Assistant Examiner.

1. AN AT LEAST PARTLY SELF ACTING GUN WHICH COMPRISES, IN COMBINATION, ABREECH CASING, A BREECH BODY GUIDED IN SAID BREECH CASING SO AS TO BESLIDABLE LONGITUDINALLY THEREIN, SAID BREECH BODY BEING PROVIDED WITH ALONGITUDINAL RECESS OPENING INTO THE REAR FACE OF SAID BREECH BODY,CARTRIDGE FEEDING MEANS OPERATIVELY CONNECTED WITH SAID BREECH BODY, ATLEAST ONE LOCKING MEMBER MOVABLY CARRIED BY SAID BREECH BODY AND ADAPTEDTO COOPERATE WITH SAID BREECH CASING, AT LEAST ONE CONTROL MEMBERSLIDABLE LONGITUDINALLY IN SAID RECESS OF SAID BREECH BODY FOR ACTUATINGSAID LOCKING MEMBER TO MOVE IT INTO COOPERATING LOCKING POSITION WITHRESPECT TO SAID BREECH CASING, A CAP LOCATED OPPOSITE SAID RECESSSLIDABLY MOUNTED LONGITUDINALLY WITH RESPECT TO SAID BREECH BODY ANDFREE FROM CONTACT WITH SAID BREECH CASING, ABUTMENT MEANS CARRIED BYSAID CAP AND SAID BREECH BODY FOR LIMITING THE REARWARD DISPLACEMENT OFSAID CAP WITH RESPECT TO SAID BREECH BODY, AND RESILIENT MEANSINTERPOSED BETWEEN SAID CAP AND SAID BREECH BODY FOR URGING SAID BREECHBODY FRONTWARDLY WITH RESPECT TO SAID CAP.